Was just talking with my dad--who is a fair classical pianist and of the generation of Gould etc.
He definitely echoes your feelings re: Gould.
He also recalls seeing Ashkenazy,Isaac Stern and 'some other famous guy' play some Brahms trios at a packed auditorium in Miami in the early to mid eighties.--Ashkenazy came running into the auditorium at the last moment wearing a black cape with a red velvet lining....My dad is guessing that they may have just sat down together cold..thats the command of the music that they had.